Rapid identification of Agrobacterium species by staircase electrophoresis of low molecular weight RNA profiles

Several plant species are infected by different species of the genus Agrobacterium. One problem is that no rapid and sensitive method is available for the identification of isolates of Agrobacterium at the species level. The usefulness of LMW RNA profiles for the identification of Agrobacterium species was examined. The profiles of strains belonging to the proposed species were identical to those of the type strain of each species except in two cases. In A. radiobacter, two groups of strains with different tRNA profiles were detected and in A. rhizogenes two groups with different 5S rRNA zones were found. Nevertheless, with the LMW RNA profiles it was possible to assign any isolate to one of each group within these species. The results obtained showed that all isolates studied here can be assigned to a species of Agrobacterium and hence that LMW RNA profiles offer a suitable method for the identification of tumor-inducing bacteria.